Emperor Napoleon III of France gave the shop of Henry Poole & Co its first Royal warrant.
Some of the high-profile clients included Prince Otto von Bismarck, Queen Alexandra, and Edward VII as Prince of Wales.
Edward VII's wife, Queen Alexandra bought her family gifts there.
His Royal Highness Prince Alfred The Duke of Edinburgh, King Leopold II of the Belgians, and His Royal Highness Prince Louis of Hesse were customers of Henry Poole & Co.
https://www.youtube.com/watch?v=Uklt1fbkyPA
Insights into the original Saville Row tailor